Catalytic cracking and fluid coking flue gas ducts



G. KRATSIOS July 12, 1966 CATALYTIC CRACKING AND FLUID COKING FLUE GAS DUCTS Filed April 28, 1964 INVENTOR G0GE A664 719/05 BY M d A M ATTORNEY United States Patent York Filed Apr. 28, 1964, Ser. No. 363,217 4 Claims. (Cl. 137317) This invention relates to a novel duct arrangement, and particularly to a novel blanking plate useful in the process industry for connecting future duct work to existing flue gas duct work.

In the process industry, and particularly in catalytic cracking and fluid coking units, it is often necessary to initially construct the flue gas piping or flue gas duct work for the unit with the possibility that in the future the duct work will be changed. Accordingly, it is conventional practice to provide a plurality of Ts in the flue gas duct work at various locations each T blanked olf by a suitable closure or blanking plate. As the need arises, a new duct is joined to a particular T and the closure for that T removed.

The problem arises that the closure must be removed prior to connecting the new duct to the T, requiring generally that the entire unit be shut down. Expensive and large gate or globe valves may be used to close off a T to avoid shutdown, but this has many obvious disadvantages. No other prior satisfactory solution to avoid shutdown is known to applicant.

Accordingly, it is an object of the invention to provide a novel closure or blanking plate for an existing flue gas duct T wherein a new duct can be connected to the T and the closure removed without the necessity of shutting down the entire unit. It is also an object of the invention to achieve this in as easy and inexpensive a manner as possible.

In accordance with the invention, in a unit having at least one existing flue gas duct, and a T or other connecting member in the duct, there is provided by the T or connecting member a flanged open end, and a closure sealing the open end, one side of the closure being pivotally supported on the duct flange. A new duct is secured to the existing duct, the new duct having an open end which is in register with the existing duct open end. The new duct also encompasses the existing duct closure and fastening means therefor. The fastening means however have portions exposed through the flange and are suitably arranged so that by turning or otherwise moving them the closure is released from sealing engagement with the existing duct flange. Preferably, the new duct is provided with a well arranged to receive the closure as it pivotally drops away from the existing duct open end.

The arrangement in accordance with the invention has the advantage that the new ducts can be fastened to the existing duct T with the existing duct closure in place and the unit operating. Subsequently, without shutting down the unit, the closure can be removed from the existing duct T, and flue gas can be allowed to flow through the new duct.

It should be noted that the closure is left within the new duct well as long as the new duct is used.

These and other advantages will become apparent upon further consideration of the specification with reference to the accompanying drawings in which:

FIGURE 1 is a section elevation view of a duct arrangement in accordance with the invention;

FIGURE 2 is a section view taken along line 2-2 of FIG. 1; and

FIGURE 3 is a partial section view on an enlarged scale taken along line 3-3 of FIG. 2.

3,260,277 Patented July 12, 1966 Referring to FIG. 1, a flue gas duct 12 is provided with a T 14, the T having an axial open end 16 and a continuous flange 18 around the periphery of the open end. The flange 18 may have a radial width somewhat greater than that of a conventional flange connection.

Along the bottom side 20 of the flange 18, a pair of spaced lugs 24 are mounted, with a pivot rod or connection 26 extending between the lugs. By means of the lugs 24 and pivot rod 26, a blanking plate or closure 22 is pivotally attached to the flange covering the T open end 16. Preferably the pivot connection 26 is a horizontally disposed rod or pin. The plate or closure 22 is held in sealing engagement with the flange 18 by means of a plurality of fastening members, bolts 28, engaging nuts 30 along the periphery of the blanking plate. The bolts are also seated in a plurality of nuts 32 welded to the outside face 34 of the flange and spaced coaxially with the nuts 30. Between the flange and blanking plate is an annular seal 36 of lesser dimension than that of the ring of fastening members 28.

A future duct consists of member 38 having an enlarged end 40 suitably joined to it, for instance by frusto-conical expansion member 42. The end 40 is generally circular at the top, but is provided With a cubical well 44 at the bottom. A flange 46 extending outwardly in this embodiment is provided around most of the periphery of the end 40 of the new duct adapted to engage the periphery of flange 18 of the existing duct, except in the area of the well 44 where the mating face 48 of the well engages the periphery of bottom portion 20 of the flange 18. Bolts or other suitable fastening members 50 secure the end 40 of the new duct to the flange 18. As an alternative, the end 40 could be welded to the existing duct flange 18.

After attaching the new duct to the existing duct T, the blanking plate or cover 22 is released from sealing engagement. To accomplish this, the bolts 28 are turned in the seats 32 on the flange until the blanking plate is released, such that it falls away from the opening 16 into the well 44 of the new duct. The well 44 is dimensioned so that it can receive the blanking plate and retain it out of the flow path of the gases from the T 14 through the new duct. The annular seal 36 isan integral part of the plate 22 and is removed from the flange 18 with the plate.

The bolts 28 are suitably fitted within the seats 32 on the flange to act as a seal against escape of gases through the seats 32. After the plate 22 is released, the seats 32 are suitably seal welded against the escape of gases.

It should now be apparent that the invention allows the connection of a new duct to an existing duct without shutting down the catalytic cracking unit or fluid coking unit. It eliminates the necessity of large gate or globe valves heretofore used, and constitutes a more positive closure and opening arrangement than a valve. Further, a new duct can be attached to an existing duct T and made functionally operative therewith in a very short time.

It will be apparent that the invention is of particular value with respect to high temperature flue gas ducts for catalytic cracking and fluid coking units.

Although the invention has been described with reference to a particular embodiment, many variations will be apparent to those skilled in the art and within the scope of the following claims. For instance, the concepts of the invention can be applied to any conventional flanged bolted head of an existing duct. The new duct simply is provided with an enlarged end, having a well capable of receiving the existing duct head. The new duct is adapted to be welded or otherwise fastened to the existing duct flange. In this respect, however, the mode of fastening must be such that the bolts for the existing duct head are exposed following attachment of the new duct to the existing duct. The pivot connection can be aflixed either to the new duct or existing duct as long as it directs the existing duct head into the well out of the flow path of the gases.

What is claimed is:

1. A duct arrangement comprising in combination an existing duct defining an open end;

a closure;

fastening means securing the closure in sealing engagement 'with the existing duct to close said open end;

a new duct also defining an open end;

means for securing the new duct to the existing duct so that the open ends are in register, the new duct enveloping the existing duct closure;

the fastening means having portions thereof exposed to the outside of the existing duct when the new duct is secured to the existing duct adapted for release of the closure from sealing engagement.

2. A duct arrangement comprising in combination an existing approximately horizontal circular duct defining an open end;

a closure adapted to cover the open end;

the existing duct including a peripheral flange around said open end;

means along the lower side of the existing duct flange pivotally supporting the closure relative the flange;

a plurality of fastening means equally spaced near the periphery of the existing duct flange extending through the flange and adapted to hold the closure in sealing engagement with the flange to close said open end;

a new duct defining an open end, the new duct being adapted for attachment to the existing duct so that said open ends are in register, the new duct enveloping the existing duct closure and fastening means;

the fastening means having portions thereof exposed to the outside of the existing duct when the new duct is secured to the existing duct adapted for release of the closure from sealing engagement.

3. A duct arrangement according to claim 2 wherein said new duct is provided with a well along the bottom side thereof adapted to receive the closure when the latter is released from sealing engagement with the existing duct flange, the well retaining said closure out of the flow path of gases in the duct.

4. A duct arrangement comprising in combination an existing approximately horizontal circular duct defining an open end, the existing duct including a continuous peripheral radially extending flange around the open end;

a closure adapted to cover the open end, the enclosure including an annular washer integral therewith adapted to engage said flange;

means along the lower side of the existing duct flange pivotally supporting the closure on the flange;

a plurality of bolt means equally spaced around the periphery of the existing duct flange extending through the flange;

means on the closure arranged to engage the bolt means to hold the closure so that the Washer thereof is in sealing engagement with the flange;

a new duct defining an open end, the new duct being adapted for attachment to the existing duct so that said open ends are in register, the new duct enveloping the existing duct closure and bolt means;

the means on the closure engaging the bolt means being arranged whereby the latter when turned from the outside of the flange release the closure from sealing engagement with the existing duct flange;

the new duct having a well along the bottom side thereof adapted to receive the closure when released and to retain it out of the flow path of gases from the existing duct through the new duct.

No references cited.

M. CARY NELSON, Primary Examiner.

W. CLINE, Assistant Examiner. 

1. A DUCT ARRANGEMENT COMPRISING IN COMBINATION AN EXISTING DUCT DEFINING AN OPEN END; A CLOSURE; FASTENING MEANS SECURING THE CLOSURE IN SEALING ENGAGEMENT WITH THE EXISTING DUCT TO CLOSE SAID OPEN END; A NEW DUCT ALSO DEFINING AN OPEN END; MEANS FOR SECURING THE NEW DUCT TO THE EXISTING DUCT SO THAT THE OPEN ENDS ARE IN REGISTE, THE NEW DUCT ENVELOPING THE EXISTING DUCT CLOSURE; THE FASTENING MEANS HAVING PORTIONS THEREOF EXPOSED TO THE OUTSIDE OF THE EXISTING DUCT WHEN THE NEW DUCT IS SECURED TO THE EXISTING DUCT ADAPTED FOR RELEASE OF THE CLOSURE FROM SEALING ENGAGEMENT. 